Nuclear Theory·nucl-th

Wednesday·April 13, 2016

13 papers—10 primary·3 cross-listed

11
[Submitted on 12 Apr 2016] (cross-list from hep-ph)
Thoughts on heavy-ion physics in the high luminosity era: the soft sector
Federico Antinori🇮🇹 · Francesco Becattini🇮🇹 · Peter Braun-Munzinger🇩🇪 · Tatsuya Chujo🇯🇵 · Hideki Hamagaki🇯🇵 · John Harris🇬🇧 · Ulrich Heinz🇺🇸 · Boris Hippolyte🇫🇷 · Tetsufumi Hirano🇺🇸 · Barbara Jacak🇺🇸 · Dmitri Kharzeev🇺🇸 · Constantin Loizides🇺🇸 and 19 other authors
This document summarizes thoughts on opportunities in the soft-QCD sector from high-energy nuclear collisions at high luminosities.
Comments:
19 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1604.03310 [pdf]
11 citations
12
[Submitted on 12 Apr 2016] (cross-list from nucl-ex)
Isomer shift and magnetic moment of the long-lived 1/2 $^{+}$ isomer in $_{30}^{79}$ Zn $_{49}$ : signature of shape coexistence near $^{78}$ Ni
X.F. Yang🇧🇪 · C. Wraith🇬🇧 · L. Xie🇬🇧 · C. Babcock🇬🇧 · J. Billowes🇬🇧 · M.L. Bissell🇧🇪 · K. Blaum🇩🇪 · B. Cheal🇬🇧 · K.T. Flanagan🇬🇧 · R.F. Garcia Ruiz🇧🇪 · W. Gins🇧🇪 · C. Gorges🇩🇪 and 12 other authors
Collinear laser spectroscopy has been performed on the $_{30}^{79}$ Zn $_{49}$ isotope at ISOLDE-CERN. The existence of a long-lived isomer with a few hundred milliseconds half-life was confirmed, and the nuclear spins and moments of the ground and isomeric states in $^{79}$ Zn as well as the isomer shift were measured. From the observed hyperfine structures, spins $I = 9/2$ and $I = 1/2$ are firmly assigned to the ground and isomeric states. The magnetic moment $μ$ ( $^{79}$ Zn) = $-$ 1.1866(10) $μ_{N}$ , confirms the spin-parity $9/ 2^{+}$ with a $ν g_{9/2}^{- 1}$ shell-model configuration, in excellent agreement with the prediction from large scale shell-model theories. The magnetic moment $μ$ ( $^{79 m}$ Zn) = $-$ 1.0180(12) $μ_{N}$ supports a positive parity for the isomer, with a wave function dominated by a 2h-1p neutron excitation across the $N = 50$ shell gap. The large isomer shift reveals an increase of the intruder isomer mean square charge radius with respect to that of the ground state: $δ ⟨ r_{c}^{2} ⟩^{79, 79 m}$ = +0.204(6) fm $^{2}$ , providing first evidence of shape coexistence.
Comments:
5 pages, 4 figures, 1 table, Accepeted by Phys. Rev. Lett. (2016)
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1604.03316 [pdf]
PRL(2016)·87 citations
13
[Submitted on 12 Apr 2016] (cross-list from physics.comp-ph)
Relativistic hydrodynamics on graphics processing units
Jan Sikorski · Sebastian Cygert · Joanna Porter-Sobieraj · Marcin Słodkowski · Piotr Krzyżanowski · Natalia Książek · Przemysław Duda
Hydrodynamics calculations have been successfully used in studies of the bulk properties of the Quark-Gluon Plasma, particularly of elliptic flow and shear viscosity. However, there are areas (for instance event-by-event simulations for flow fluctuations and higher-order flow harmonics studies) where further advancement is hampered by lack of efficient and precise 3+1D~program. This problem can be solved by using Graphics Processing Unit (GPU) computing, which offers unprecedented increase of the computing power compared to standard CPU simulations. In this work, we present an implementation of 3+1D ideal hydrodynamics simulations on the Graphics Processing Unit using Nvidia CUDA framework. MUSTA-FORCE (MUlti STAge, First ORder CEntral, with a~slope limiter and MUSCL reconstruction) and WENO (Weighted Essentially Non-Oscillating) schemes are employed in the simulations, delivering second (MUSTA-FORCE), fifth and seventh (WENO) order of accuracy. Third order Runge-Kutta scheme was used for integration in the time domain. Our implementation improves the performance by about 2~orders of magnitude compared to a~single threaded program. The algorithm tests of 1+1D~shock tube and 3+1D~simulations with ellipsoidal and Hubble-like expansion are presented.
Comments:
3 pages, 3 figures, SQM2015 proceedings submitted to Journal of Physics: Conference Series (JPCS) - IOP Conference Series
Subjects:
Computational Physics (physics.comp-ph); Nuclear Theory (nucl-th)
arXiv:
1604.03360 [pdf]
J.Phys.Conf.Ser.(2014)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Thoughts on heavy-ion physics in the high luminosity era: the soft sector

Isomer shift and magnetic moment of the long-lived 1/2+ isomer in 3079​Zn49​: signature of shape coexistence near 78Ni

Relativistic hydrodynamics on graphics processing units

Affiliations

Isomer shift and magnetic moment of the long-lived 1/2 $^{+}$ isomer in $_{30}^{79}$ Zn $_{49}$ : signature of shape coexistence near $^{78}$ Ni